Is surveilluminescence an April fool's joke or is the science legitimate? 
This website and in particular this paper, describe how one can 'see' the 'sightfield' of a camera. To quote,

[A] linear array of computer-controlled LED lights is held in front of
  a surveillance camera.  Even though the camera is concealed inside a
  dark dome with a shroud to hide any information about which way the
  camera is aimed, its sightfield may be visualized by abakography.  An
  abakographic wand is moved through the space to trace out a
  “darkpainting” or “sightpainting” (inverse “lightpainting”) that
  allows one or more abakographic cameras (e.g.  one or more people
  wearing Meta-View Spaceglasses), to observe the surveillance camera’s
  sightfield. This may be done by way of 3D (three-dimensional) AR
  (Augmediated Reality). The color change of the abakographic wand (from
  black to blue in this example) indicates, over time (animated from
  left-to-right), the surveillance camera’s field-of-view and extent of
  coverage.


Accompanying this figure is the following description. 

A PixStix Abakographer is swept through space like a wand. Typically
  there are hundreds of light sources along its length, but for
  simplicity, only 8 are shown here, numbered L1 through L8. Here the
  lightfield test color, is green. When the lightfield falls within the
  sightfield of a surveillance camera, the color changes to the
  abakographic color which is red in this example. A second camera, the
  abakographic camera, captures the abakograph of the wand, to build up
  a representation of the sight-field over time.  The PixStix
  Abakographer contains a processor to present a special pattern, while
  sensing changes in response to nearby surveillance cameras.

Can someone explain how this works in simple terms (and without jargon or quoting verbatim from the paper)? How can a series of LEDs be used to detect whether a camera is 'seeing' them?
 A: From the linked paper:

There are three ways in which a sightfield may be visualized [...]

*

*a "friendly" camera that we control;

*a hostile camera that is controlled by another entity, to which we may apply signals intelligence to receive its signals;

*a camera we can't receive signals from, possibly because it does not yet exist

[...]
Scenario (3) arises when we are unable to do so [...]. In this case we merely affix a small wireless camera into the space in alignment with the existing (unreadable) or not yet existing (i.e. proposed) camera/camera-location.
[...]
By "painting" with a test color or test pattern, a response
manifests itself and is sensed, for which the abakographic wand displays an abakographic pattern (different than the
test pattern).

In other words, the system is dependent on getting access (wittingly or unwittingly) to the video recorded by the surveillance camera, or a stand-in camera put in its place. When the surveillance camera detects the wand, the wand lights a corresponding pixel for the light-painting picture. It doesn't have any novel way of detecting whether photons are landing on a camera sensor or not; it simply observes the camera's output. So the science is legitimate, and the system is realistic — they just try not to mention the major caveat for PR purposes.
